Pump Housing Part

ABSTRACT

The invention relates to a housing part, in particular a pump housing part, having a metering unit fastened in a pressure-tight manner to the housing part so as to be detachable, that is to say separable repeatedly without destruction. In order to optimize the fastening of the functional part, a collar is provided on the housing part, the collar having a tapered collar face against which a first tapered face of at least one tapered element bears, the tapered element having a second tapered face with which a tapered ring face of a tapered ring comes into contact when the tapered ring is moved from an open position into a closed position in order to press a positively locking face of the tapered element against a mating face which is provided on the functional unit.

The invention relates to a housing part, in particular a pump housing part, having a functional unit, in particular a metering unit, that is secured releasably, or in other words repeatedly separably without destruction, and in pressure-tight fashion to the housing part.

PRIOR ART

Conventional metering units for instance have a flange with through holes for screws with which the flange is secured to the pump housing part. The orientation of the metering unit with the pump housing part is defined by the disposition of the through holes. This can lead to space conflicts when the pump housing part or the associated pump is installed in a motor vehicle. It is also possible to secure a metering unit to a housing part with the aid of a union nut. The union nut requires a relatively large amount of free space, to make access possible for an installation tool.

The object of the invention is to optimize the securing of a functional unit, in particular a metering unit, to a housing part, in particular a pump housing part.

ADVANTAGES OF THE INVENTION

In a housing part, in particular a pump housing part, having a functional unit, in particular a metering unit, which is secured releasably, that is, repeatedly nondestructively separably, and in pressure-tight fashion on the housing part, attained in that on the housing part, a collar is provided, which has a tapered collar face on which a first tapered face of at least one tapered element rests, which element has a second tapered face on which a tapered ring face of a tapered ring comes into contact when the tapered ring is moved from an open position to a closed position, in order to press a positive-engagement face of the tapered element against a counterpart face that is provided on the functional unit. The invention creates an easily installed positive- and nonpositive-engagement connection between the functional unit and the housing part. The functional unit can be oriented in arbitrary directions relative to the housing part. No screw bores need to be made in the housing part. For both the connection itself and for installation, only little space is needed.

A preferred exemplary embodiment of the housing part is characterized in that the collar extends over a circumferential angle of more than 180° and less than 360°, so that the collar is not embodied continuously in the circumferential direction but instead has a mounting opening. The mounting opening enables insertion of the tapered element between the counterpart face and the tapered collar face.

A further preferred exemplary embodiment of the housing part is characterized in that the collar extends over a circumferential angle of approximately 270°. The mounting opening then extends over a circumferential angle of approximately 90°. This facilitates the insertion of the tapered element or a plurality of tapered elements.

A further preferred exemplary embodiment of the housing part is characterized in that at least two tapered elements are disposed between the tapered collar face and the counterpart face. As a result, stable securing of the functional unit to the pump housing part is assured.

A further preferred exemplar embodiment of the housing part is characterized in that the counterpart face is provided on a rim that is embodied on the functional unit. Preferably, the rim extends in the radial direction on the side of the functional unit toward the pump housing part.

A further preferred exemplary embodiment of the housing part is characterized in that the second tapered face is disposed at an angle of 81 to 89° relative to the positive-engagement face of the tapered element. Preferably, an angle of approximately 85° is enclosed between the second tapered face and the positive-engagement face.

A further preferred exemplary embodiment of the housing part is characterized in that the second tapered face is disposed at an angle of 40 to 90° relative to the first tapered face of the tapered element. Preferably, an angle of approximately 65° is enclosed between the first and second tapered faces of the tapered element.

A further preferred exemplary embodiment of the housing part is characterized in that the tapered ring has an annular groove extending in the circumferential direction. The annular groove creates an engagement capability for an installation tool, with which the tapered ring can be loosened as needed in order to dismantle the functional unit.

Further advantages, characteristics and details of the invention will become apparent from the ensuing description, in which one exemplary embodiment is described in detail in conjunction with the drawings. The characteristics recited in the claims and mentioned in the description may each be essential to the invention individually or in arbitrary combination with one another.

DRAWINGS

Shown are:

FIG. 1, a pump housing part with a metering unit in the preassembled state, in section;

FIG. 2, an enlarged view of a detail marked II in FIG. 1;

FIG. 3, the pump housing part of FIG. 1 with the metering unit in the installed state, in section; and

FIG. 4, an enlarged view of a detail marked IV in FIG. 3.

DESCRIPTION OF THE EXEMPLARY EMBODIMENT

In FIG. 1, a pump 1 with a pump housing part 2 is shown in section. The pump 1 is preferably a radial piston pump, which is driven by a drive shaft that has an eccentric shaft portion. The ends of three pistons arranged in a star pattern are in contact with the eccentric shaft portion. The ends of the piston facing away from the drive shaft define work chambers, which are also called pump chambers. Each of the work chambers communicates with a low-pressure region via a respective suction valve and with the interposition of a metering unit 4.

The work chambers furthermore communicate via pressure valves with a high-pressure fuel reservoir, also known as a common rail, or simply rail for short. From the common rail, high-pressure lines lead to fuel injection valves. The common rail is in communication with the low-pressure region via a pressure limiting valve. A rail pressure sensor, by way of which the pressure in the common rail is detected, is also attached to the common rail.

The pump 1 serves to pump fuel from the low-pressure region into the common rail. Upon intake, the suction valves open, while the pressure valves are conversely closed. Via the metering unit 4, the pumping capacity of the high-pressure pump 1 can be controlled. When fuel is being pumped into the common rail, the suction valves are closed and the pressure valves are open. The metering unit 4 includes a metering unit housing 5, which is shown in FIG. 1 in the preassembled state.

In FIG. 2, a detail II from FIG. 1 is shown enlarged. The metering unit 4, on its underside, has a sealing face 6 that rests on a flat attachment face 7 that is provided on the pump housing part 2. The pump housing part 2 also has a guide face 8 in the form of a circular-cylindrical jacket, which is defined at the bottom by a rim 9 that protrudes radially outward from the guide face 8.

A tapered ring 10 is guided, movably up and down, on the guide face 8. The tapered ring 10 takes the form of a sleeve in the shape of a circular-cylindrical jacket, which is provided radially on the outside of its upper end with an annular groove 11. The annular groove 11, extending in the circumferential direction, has a rectangular cross section and represents an engagement capability for a tool. From the annular groove 11, a tapered ring face 12 extends downward, radially outward on the tapered ring. The tapered ring face 12 forms a cone that tapers from the annular groove 11 toward the rim 9.

The pump housing part 2, above the attachment face 7 for the metering unit 4, has a recess that is defined by a collar 14. The collar 14 is not embodied continuously in the circumferential direction but instead is interrupted in a mounting region. Radially inward, the collar has an introduction funnel, which tapers toward the attachment face 7. A tapered collar face 16 begins at the inner end of the introduction funnel 15 and is inclined downward at an angle of approximately 35° to a horizontal line. The tapered collar face 16 is disposed at a distance from the collar 9.

A tapered element 20 is disposed between the tapered collar face 16 and the collar 9. The tapered element 20, viewed in cross section, has a first tapered face 21, which rests on the tapered collar face 16 of the pump housing part 2. Radially inward, the tapered element 20 has a second tapered face 22, which forms a bearing face for the tapered ring face 12 that is embodied radially outward on the tapered ring 10. The second tapered face 22 is disposed at an angle of approximately 65° to the first tapered face 21. The tapered element 20 extends over a circumferential angle range of less than 180°. For securing the metering unit 4 to the pump housing part 2, two tapered elements, preferably of equal size, are used.

On its underside, the tapered element 20 has a positive-engagement face 24, which rests partly on a counterpart face 25 that is provided on the top side of the rim 9 of the pump housing part 2. In FIGS. 1 and 2, the metering unit 1 is shown in the preassembled, unfastened state. In this state, the metering unit 4 can be rotated relative to the pump housing part 2. In assembly, the metering unit 4 is inserted into the opening, defined by the collar 14, in the pump housing part 2. Then the tapered elements are thrust through the mounting opening into the groove that is defined by the tapered collar face 16 and the counterpart face 25 of the rim 9. Next, the metering unit 4 is oriented in such a way that a plug, provided on the metering unit 4, points in the desired direction. Finally, the tapered ring 10 is moved downward, as indicated in FIG. 2 by an arrow 28.

In FIGS. 3 and 4, the fully assembled state of the metering unit 4 on the pump housing part 2 is shown. In FIG. 4, it can be seen that the tapered ring 10 has been press-fitted into the conically inward-tapering annular chamber between the guide face 8 and the second tapered face 22 in such a way that the tapered element 20 has been displaced radially outward. Via the conical tapered faces 21 and 22 on the tapered element 20, the tapered element 20 is firmly clamped between the first tapered face 21 and the counterpart face 25. By means of a suitable inclination of the tapered faces, it is assured that the tapered ring 10 cannot come loose unintentionally. 

1-8. (canceled)
 9. In a pump housing part metering unit secured thereon, and attachment means for releasably repeatedly nondestructively separably securing the metering unit in pressure-tight fashion on the housing part, the attachment means comprising a collar on the housing part and having a tapered collar face, at least one tapered element having a first tapered face resting on the tapered cellar face and a positive engagement face, the element having a second tapered face, a tapered ring movable from an open to a closed position and having tapered ring face contacting the second tapered face when the tapered ring is moved from the open position to the closed position pressing the positive-engagement face of the tapered element against a counterpart face on the functional unit.
 10. The housing part as defined by claim 9, wherein the collar extends over a circumferential angle of more than 180° and less than 360°, whereby the collar is not embodied continuously in the circumferential direction but instead has a mounting opening.
 11. The housing part as defined by claim 10, wherein the collar extends over a circumferential angle of approximately 270°.
 12. The housing part as defined by claim 9, wherein at least two tapered elements are disposed between the tapered collar face and the counterpart face.
 13. The housing part as defined by claim 10, wherein at least two tapered elements are disposed between the tapered collar face and the counterpart face.
 14. The housing part as defined by claim 11, wherein at least two tapered elements are disposed between the tapered collar face and the counterpart face.
 15. The housing part as defined by claim 9, further comprising a rim on the metering unit, the counterpart face being embodied on the functional unit.
 16. The housing part as defined by claim 10, further comprising a rim on the metering unit, the counterpart face being embodied on the functional unit.
 17. The housing part as defined by claim 12, further comprising a rim on the metering unit, the counterpart face being embodied on the functional unit.
 18. The housing part as defined by claim 9, wherein the second tapered face is disposed at an angle of 81 to 89° relative to the positive-engagement face of the tapered element.
 19. The housing part as defined by claim 10, wherein the second tapered face is disposed at an angle of 81 to 89° relative to the positive-engagement face of the tapered element.
 20. The housing part as defined by claim 12, wherein the second tapered face is disposed at an angle of 81 to 89° relative to the positive-engagement face of the tapered element.
 21. The housing part as defined by claim 15, wherein the second tapered face is disposed at an angle of 81 to 89° relative to the positive-engagement face of the tapered element.
 22. The housing part as defined by claim 9, wherein the second tapered face is disposed at an angle of 40 to 90° relative to the first tapered face of the tapered element.
 23. The housing part as defined by claim 10, wherein the second tapered face is disposed at an angle of 40 to 90° relative to the first tapered face of the tapered element.
 24. The housing part as defined by claim 15, wherein the second tapered face is disposed at an angle of 40 to 90° relative to the first tapered face of the tapered element.
 25. The housing part as defined by claim 18, wherein the second tapered face is disposed at an angle of 40 to 90° relative to the first tapered face of the tapered element.
 26. The housing part as defined by claim 9, wherein the tapered ring has an annular groove extending around its outer circumference.
 27. The housing part as defined by claim 10, wherein the tapered ring has an annular groove extending around its outer circumference.
 28. The housing part as defined by claim 25, wherein the tapered ring has an annular groove extending around its outer circumference. 